U.S. patent application number 15/437964 was filed with the patent office on 2017-08-24 for system, devices, and method for on-body data and power transmission.
The applicant listed for this patent is MC10, Inc.. Invention is credited to Alexander J. Aranyosi, Valerie Susan Hanson, Bryan McGrane, Jeffrey Model, Milan Raj, Hoi-Cheong Steve Sun.
Application Number | 20170244543 15/437964 |
Document ID | / |
Family ID | 59629529 |
Filed Date | 2017-08-24 |
United States Patent
Application |
20170244543 |
Kind Code |
A1 |
Raj; Milan ; et al. |
August 24, 2017 |
SYSTEM, DEVICES, AND METHOD FOR ON-BODY DATA AND POWER
TRANSMISSION
Abstract
An on-body sensor system includes a hub configured to be
attached to a surface of a user. The hub being further configured
to transmit electrical power and/or data signals into the surface
and to receive response data signals from the surface. The system
further including at least one sensor node configured to be
attached to the surface. The sensor node being further configured
to receive the electrical power and data signals from the hub
through the surface and to transmit the response data signals into
the surface. The electrical power from the hub can power the sensor
node and cause or enable the at least one sensor node to generate
sensor information that is transmitted back to the hub within the
response data signals.
Inventors: |
Raj; Milan; (Natick, MA)
; McGrane; Bryan; (Cambridge, MA) ; Model;
Jeffrey; (Cambridge, MA) ; Sun; Hoi-Cheong Steve;
(Lexington, MA) ; Aranyosi; Alexander J.;
(Medford, MA) ; Hanson; Valerie Susan; (Medford,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MC10, Inc. |
Lexington |
MA |
US |
|
|
Family ID: |
59629529 |
Appl. No.: |
15/437964 |
Filed: |
February 21, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62298296 |
Feb 22, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 7/033 20130101;
Y04S 40/18 20180501; H04B 13/005 20130101; H04L 67/04 20130101;
H04Q 2209/40 20130101; H04W 52/00 20130101; H04L 67/12 20130101;
H04L 67/22 20130101; H04Q 2209/43 20130101; H04Q 9/00 20130101 |
International
Class: |
H04L 7/033 20060101
H04L007/033; H04L 29/08 20060101 H04L029/08; H04B 13/00 20060101
H04B013/00 |
Claims
1. An on-body sensor system comprising: a hub configured to be
attached to a surface of a user, the hub being further configured
to transmit electrical power and data signals into the surface and
to receive response data signals from the surface; and at least one
sensor node configured to be attached to the surface, the at least
one sensor node being further configured to receive the electrical
power and data signals from the hub through the surface and to
transmit the response data signals into the surface, wherein the at
least one sensor node is powered by the electrical power received
from the hub to generate sensor information that is transmitted
back to the hub within the response data signals.
2. The sensor system of claim 1, wherein the hub is further
configured to modulate the electrical power with the data signals
prior to transmitting the electrical power and data signals into
the surface.
3. The sensor system of claim 2, wherein with the electrical power
is an alternating current.
4. The sensor system of claim 2, wherein the alternating current
electrical power is about 1.5 milliwatts.
5. The sensor system of claim 2, wherein the at least one sensor
node is further configured to demodulate the electrical power to
obtain the data signals.
6. The sensor system of claim 1, wherein the hub further includes
one or more power sources that store electrical energy, and the hub
is configured to transmit the electrical energy to the at least one
sensor node as the electrical power.
7. The sensor system of claim 1, wherein the at least one sensor
node does not include a chemical energy power source.
8. The sensor system of claim 1, wherein the at least one sensor
node comprises a plurality of sensor nodes, each sensor node of the
plurality of sensor nodes including an application-specific sensor
having a different sensing modality among the plurality of
application-specific sensors.
9. The sensor system of claim 1, wherein the at least one sensor
node is a heat flux sensor, an accelerometer, an electrocardiogram
sensor, a pressure sensor, a heart rate monitor, a galvanic skin
response sensor, a sweat sensor, a non-invasive blood pressure
sensor, or a blood oxygen saturation monitor.
10. The sensor system of claim 1, wherein the at least one sensor
node includes a processor configured to process the data signals
for executing one or more application-specific algorithms.
11. The sensor system of claim 1, wherein the hub includes memory
configured to aggregate sensor information from the at least one
sensor node.
12. The sensor system of claim 11, wherein the hub is further
configured to communicate with an off-body computer device for
processing and/or storing of the sensor information.
13. The sensor system of claim 1, wherein the hub includes at least
one electrical contact for transmitting the electrical power and
data signals into the surface.
14. The sensor system of claim 13, wherein the at least one
electrical contact is in direct contact with the surface.
15. The sensor system of claim 13, wherein the at least one
electrical contact is off of the surface.
16. The sensor system of claim 1, wherein the surface is skin of
the user.
17. The sensor system of claim 1, wherein the at least one sensor
node further includes a phase lock loop, and the at least one
sensor node synchronizes with the hub based on the phase lock
loop.
18. The sensor system of claim 1, wherein the at least one sensor
node is a smart sensor node.
19. The sensor system of claim 1, wherein the at least one sensor
node is a dumb sensor node.
20. The sensor system of claim 1, wherein the hub and the at least
one sensor node each includes an adhesive element to attach the hub
and the at least one sensor node to the surface of the user.
21. The sensor system of claim 20, wherein the adhesive element is
an adhesive tape that is removable from the hub and the at least
one sensor node.
22. A method of synchronizing nodes within an on-body sensor
network, the method comprising: transmitting, by a master hub
located on a surface of a user, an initialization electrical
current pulse into the surface; receiving, by at least one sensor
node located on the surface, the initialization electrical current
pulse from the surface; transmitting, by the at least one sensor
node, an acknowledge electrical current pulse into the surface
after a pre-determined delay and in response to receipt of the
initialization electrical current pulse; detecting, by the master
hub, the acknowledge electrical current pulse; transmitting, by the
master hub, a triggering electrical current pulse into the surface,
the triggering electrical current pulse including electrical power
and data; and receiving, by the at least one sensor node, the
triggering electrical current pulse from the surface, the
electrical power and data triggering the at least one sensor node
to begin generating sensor information.
23. The method of claim 22, further comprising: transmitting, by
the at least one sensor node, response data including the sensor
information into the surface; and receiving, by the master hub, the
response data from the surface.
24. The method of claim 23, further comprising: transmitting, by
the master hub, the response data including the sensor information
to a computer device located off of the user.
25. The method of claim 22, wherein the initialization electrical
current pulse is of a fixed duration and a fixed amplitude, and at
a dedicated initialization frequency.
26. The method of claim 25, wherein the triggering electrical
current pulse is of a fixed duration and a fixed amplitude, and at
a dedicated triggering frequency, different than the dedicated
initialization frequency.
27. The method of claim 22, wherein the initialization electrical
current pulse and the triggering electrical current pulse are about
1.5 milliwatts.
28. The method of claim 22, wherein the master hub transmits the
initialization electrical current pulse continuously, periodically,
semi-periodically, or on-demand.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to and the benefit
of U.S. Provisional Application No. 62/298,296, filed Feb. 22,
2016, entitled, "SYSTEM, DEVICES, AND METHOD FOR ON-BODY DATA AND
POWER TRANSMISSION," which is hereby incorporated by reference
herein in its entirety.
FIELD OF THE INVENTION
[0002] The present disclosure relates to on-body, multi-sensor
networks. In particular, the present disclosure relates to the
delivery of electrical power and data signals within an on-body,
multi-sensor network.
BACKGROUND OF THE INVENTION
[0003] With advancements in the manufacturing of semiconductor
devices, such devices are becoming smaller and more versatile.
These devices are spurring advancements in different and new
technological areas. One technological area is wearable devices.
Despite the advancements in the semiconductor devices themselves,
however, the current state of power sources still imposes
limitations on the semiconductor devices. In the field of wearable
devices, the form factor and longevity of wearable devices are
directly related to the on-board power sources. The power sources
for wearable devices are typically in the form of bulky (relative
to the size of the wearable devices), non-conformal batteries, such
as lithium ion batteries. The size of the batteries drives the
overall form factor of the wearable devices to be large, bulky,
and/or non-conformal, which imposes limitations and constraints on
the overall functionality of the wearable devices.
[0004] Therefore, there is a continuing need for developing
systems, methods, and devices that solve the above and related
problems.
SUMMARY OF THE INVENTION
[0005] According to some embodiments, an on-body sensor system
includes a hub and at least one sensor node. The hub is configured
to be attached to a surface (e.g., the skin) of a user. The hub is
further configured to transmit electrical power and/or data signals
into the surface (and through the skin) and to receive power and/or
data signals transmitted through skin to the surface. The at least
one sensor node is configured to be attached to the surface. The at
least one sensor node is further configured to receive the
electrical power and/or data signals from the hub through the
surface and to transmit the response data signals into the surface
(and through the skin). The electrical power from the hub powers
the at least one sensor node and causes the at least one sensor
node to generate sensor information that is transmitted back to the
hub within the response data signals.
[0006] According to some embodiments, a method of synchronizing
nodes within an on-body sensor network is disclosed. The method
includes transmitting, by a master hub located on a surface (e.g.,
skin) of a user, an initialization electrical current pulse into
the surface. The method further includes receiving, by at least one
sensor node located on the surface, the initialization electrical
current pulse from the surface. The method further includes
transmitting, by the at least one sensor node, an acknowledgment
electrical current pulse into the surface after a pre-determined
delay and in response to receipt of the initialization electrical
current pulse. The method further includes detecting, by the master
hub, the acknowledgment electrical current pulse, and transmitting,
by the master hub, a triggering electrical current pulse into the
surface. The triggering electrical current pulse including
electrical power and data. The method further includes receiving,
by the at least one sensor node, the triggering electrical current
pulse from the surface. The electrical power and data triggering
the at least one sensor node to begin generating sensor
information.
[0007] Additional aspects of the disclosure will be apparent to
those of ordinary skill in the art in view of the detailed
description of various embodiments, which is made with reference to
the drawings, a brief description of which is provided below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention will be better understood from the following
description of exemplary embodiments together with reference to the
accompanying drawings, in which:
[0009] FIG. 1 is a schematic diagram of an on-body, multi-sensor
system, in accord with aspects of the present disclosure;
[0010] FIG. 2 is a schematic diagram of a master hub and sensor
nodes of the on-body, multi-sensor system of FIG. 1, in accord with
aspects of the present disclosure;
[0011] FIG. 3 is a detailed schematic diagram of an electrical
power and data transceiver of a sensor node, in accord with aspects
of the present disclosure;
[0012] FIG. 4 is a timing diagram of electrical power and data
transmission within the on-body, multi-sensor system of FIG. 1, in
accord with aspects of the present disclosure;
[0013] FIG. 5A is a bottom view of a schematic diagram of an
exemplary sensor node, in accord with aspects of the present
disclosure;
[0014] FIG. 5B is a top view of a schematic diagram of the
exemplary sensor node of FIG. 5A, in accord with aspects of the
present disclosure;
[0015] FIG. 6A is a diagram of an integrated master hub placed on
the body of a user, in accord with accord with aspects of the
present disclosure;
[0016] FIG. 6B is a diagram of contacts of the master hub of FIG.
6A in relation to the body of the user, in accord with aspects of
the present disclosure; and
[0017] FIG. 6C is a diagram of a gap between the master hub and the
body in FIG. 6A, in accord with aspects of the present
disclosure.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0018] Although the present disclosure contains certain exemplary
embodiments, it will be understood that the disclosure is not
limited to those particular embodiments. On the contrary, the
present disclosure is intended to cover all alternatives,
modifications, and equivalent arrangements as may be included
within the spirit and scope of the disclosure as further defined by
the appended claims.
[0019] The present disclosure is directed to an on-body,
multi-sensor network. Within the network is a node, also referred
to herein as a master node or master hub. The master hub provides
the electrical power and/or data to the remaining nodes within the
network, also referred to herein as sensor nodes or sensor patches.
Both the master hub and the sensor nodes can be located on a body,
such as a user's body (e.g., human or animal body). The sensor
nodes can be distributed across the body and remote from (e.g., not
physically connected to) the master hub.
[0020] The form factor of both the master hub and the sensor nodes
can allow for the master hub and the sensor nodes to be placed on a
regular or an irregular surface of an object (e.g., the body of the
user, such as on the skin of the user). For example, the master hub
and the sensor node can be provided with one or more adhesive
surfaces (e.g., pressure sensitive adhesives, permanent adhesives,
and/or removable adhesive elements such as adhesive tapes) in order
to attach the master hub and the sensor node to the surface of the
body of the user. In accordance with some embodiments, the master
hub and/or one or more sensor nodes can be coupled (e.g., via
adhesive, stitching, or hook and loop fasteners) to clothing, a
bandage, or a brace that can be worn on the body and configured to
position the master hub and/or one or more sensor nodes in contact
with the surface of the body of the user. In accordance with some
embodiments, the master hub and/or one or more sensor nodes can be
held in place on the surface of the body by adhesive tape or a
tight fitting garment, bandage or brace.
[0021] When coupled to the surface of an object, the master hub can
supply electrical power and/or data to the sensor node through the
surface of the object, such as through the skin of the body of a
user. The sensor node acquires sensor information pertaining to the
object, such as the body of the user, and operates based on the
electrical power transmitted by the master hub through the object
to the sensor node. Thus, the network operates based on the
transmission of electrical power and/or data between nodes using a
user's body (e.g., a human or animal body) as the transmission
medium. More specifically, the network uses the skin of the user's
body as the transmission medium for electrical power and/or data
transmission. Biological tissues have noticeable reactance from 5
kHz to 1 MHz. The peak reactance is at 50 kHz. Bioimpedance of
significant physiological interest lies between 10 kHz to 100 kHz.
Beyond 100 kHz, the reactance drops rapidly allowing higher
electrical current to be injected into the body safely.
Alternatively, the reactance drop allows more reliable transmission
of electrical signals through the body at lower currents. However,
radio channels exist above 300 kHz. These radio channels can
interfere with signal of interest. Therefore, the frequency band
from 100 kHz to 300 kHz can be used for intra-body signal
transmission with the least interferences. However, other frequency
bands can be used for intra-body signal transmission depending on
the application and transceiver technologies (e.g., spread spectrum
and QAM) used. Other frequency bands that can be used for
intra-body signal transmission include, for example, bands in the 5
KHz to 10 MHz range, the 2 MHz to 30 MHz range including the 3 MHz
to 7 MHz range, and the 13 MHz to 20 MHz range.
[0022] According to some configurations of the present disclosure,
the sensor nodes do not require separate on-board electrical power
sources. Instead, the sensor nodes receive electrical power from
the master hub transmitted across the skin of the user's body. In
addition, signals and can be carried within the electrical power
signals, allowing the master hub to both power and communicate with
the sensor nodes.
[0023] Transmitting the electrical power and the data signals
through the user's body alleviates the physical burdens imposed on
sensor systems, such as each sensor node requiring a discrete,
on-board power source (and signal wires to the hub), and
facilitates a more streamlined and comfortable design. Moreover,
with the master hub as the power source, the sensor nodes can be
smaller and/or provide for greater functionality (e.g., additional
sensors) and persistence by not requiring repeated removal from the
user's body for recharging. By transmitting electrical power and/or
data through the skin of the user's body, rather than over the air,
the network can utilize lower power compared to comparable wireless
methods, while also providing a higher level of security by not
being susceptible to interception of over the air
transmissions.
[0024] Turning now to the drawings, FIG. 1 shows an on-body,
multi-sensor system 100, in accord with aspects of the present
disclosure. The system 100 includes a master hub 102 and a
plurality of sensor nodes 104a-104n (collectively referred to as
sensor nodes 104). However, although illustrated and described as a
multi-sensor system 100, the present invention includes the system
100 having only two nodes (e.g., the master hub 102 and one sensor
node 104).
[0025] The master hub 102 provides electrical power and/or data to
the sensor nodes 104 located across a body 106 of a user. More
specifically, the master hub 102 transmits the electrical power and
data to the sensor nodes 104 across the skin 106a of the body 106.
In response to electrical power and data from the master hub 102,
the sensor nodes 104 transmit data (e.g., response data) back to
the master hub 102 across the skin 106a. The response data can
include sensor information from one or more sensors of the sensor
nodes 104, which is generated and/or collected based on the sensor
nodes 104 receiving the electrical power from the master hub 102.
Sensor information includes, for example, motion information (e.g.,
acceleration), temperature (e.g., ambient and of the sensor),
electrical signals associated with cardiac activity, electrical
signals associated with muscle activity, changes in electrical
potential and impedance associated with changes to the skin,
biopotential monitoring (e.g., electrocardiography (ECG),
electromyography (EMG), and electroencephalogram (EEG)),
bioimpedance monitoring (e.g., body-mass index, stress
characterization, and sweat quantification), galvanic skin response
information, and optically modulated sensing (e.g.,
photoplethysmography and pulse-wave velocity). The response data
can also include status information about the status of the sensor
node 104 including, for example, the configuration of the node
(e.g., sensor operating parameters such as frequency or mode of
operation). Thus, the master hub 102 supplies the sensor nodes 104
with electrical power rather than, for example, the sensor nodes
104 including on-board discrete power sources, such as chemical
energy sources (e.g., batteries).
[0026] In some aspects, the master hub 102 is a standalone,
dedicated master hub. In other aspects, the master hub 102 can be
embodied in a device, an object, and/or an item. By way of example,
and without limitation, the master hub 102 can be embodied in a
device that is worn by the user, such as a fitness tracker, a smart
watch, a wristband, jewelry (e.g., rings, earrings, bracelets,
etc.), an article of clothing (e.g., shirts, gloves, hats, socks,
pants, etc.) or protective gear (e.g., helmet or body or limb
padding), etc., which contacts or is close to the skin 106a of the
user. Further, although the user of FIG. 1 is illustrated as a
human, the user can be any biological entity with skin that permits
the transmission of electrical power and/or data.
[0027] The location of the master hub 102 on the body 106 can vary.
In some aspects, the master hub 102 is centrally located on the
body 106 so that the outlying sensor nodes 104 all are
approximately the same distance from the master hub 102. Exemplary
locations for a centrally located master hub 102 include the chest,
the back, the abdomen, the upper torso, and the like. By way of
example, and without limitation, a master hub 102 centrally located
on the body 106 can be embodied in an article of clothing.
Alternatively, the master hub 102 may not be centrally located.
Instead, the master hub 102 can be located on an extremity of the
body 106, such as at the wrist, the ankle, the head, and the like.
By way of example, and without limitation, a master hub 102 located
around the wrist of the body 106 can be embodied in a smart watch.
The master hub 102 can also be embedded (e.g., hidden) in other
body worn elements, such as belts, shoes, hats, gloves, braces
(e.g., wrist, ankle, knee, chest, neck braces). The master hub 102
can also be incorporated into devices that come in contact with a
portion of the body, such as a seat, a handle (e.g., exercise bike,
treadmill, elliptical machine, dumbbell, exercise bar), or standing
platform or footrest.
[0028] In some aspects, the system 100 further includes a computer
device 108. The computer device 108 can be any smart device, such
as a smartphone, a tablet, a laptop, a desktop, etc., that is
capable of communicating with the master hub 102. Data, such as
sensor information, generated by the sensor nodes 104 can be
transmitted back to the master hub 102 as response data. From the
master hub 102, the response data can be transmitted to the
computer device 108 for additional processing, analysis, storage,
and/or transmission to additional devices or systems (e.g., the
cloud, devices or systems remote from the system 100).
Alternatively, the response data can be processed by the master hub
102 and processed response data can transmitted to the computer
device 108 for additional processing, analysis, storage, and/or
transmission to the cloud, additional devices or systems.
Communications between the master hub 102 and the computer device
108 can be wired or wireless. Preferably, communications between
the master hub 102 and the computer device 108 are based on
wireless communication protocols such as, for example, Wi-Fi,
Bluetooth, Bluetooth Low Energy, Zigbee, and the like. However, the
wireless communications can be based on other protocols, including
proprietary protocols, without departing from the concepts of the
present disclosure.
[0029] Based on the master hub 102 transmitting the electrical
power to the sensor nodes 104, the sensor nodes 104 do not require
an internal or on-board power source. Accordingly, the sensor nodes
104 can fit on the body 106 in various locations without being
constrained by the size, weight, and/or inflexibility of an
on-board power source. In doing so, the system 100 facilitates the
operation and placement of the sensor nodes 104. Further, the
sensor nodes 104 can be optimized for the particular sensing
modality of interest, which improves the sensor nodes 104 by
allowing for better signal quality, better data collection, and the
like. The electrical power and data transmitted from the master hub
102 to the sensor nodes 104 can be further tailored for each
specific sensing modality, such as transmitting data in the form of
specific algorithms for each sensor node 104 to execute.
[0030] In accordance with some embodiments, the sensor nodes 104
can include an onboard power storage component such as a battery or
a capacitor configured to store power received from the master hub
102. In this configuration, the power received from by the sensor
node 104 from the master hub 102 can be stored to allow the master
hub 102 to be charged or replaced and to accommodate short duration
power disruptions. The size of the power storage component can be
determined based on the operating parameters of the sensor node
104, such as its operating power load.
[0031] In some aspects, the sensor node 104 is a standalone device.
In other aspects, the sensor node 104 can be embodied in other
devices, objects, and/or items that come into contact with the body
106. By way of example, and without limitation, the sensor node 104
can be embodied in a device, object, and/or item that is worn by
the user, such as a wristband, jewelry (e.g., rings, earrings,
bracelets, etc.), an article of clothing (e.g., shirts, gloves,
hats, socks, pants, etc.) skin 106a of the user. By way of
additional examples, the sensor node 104 can be embodied in
furniture (e.g., chair, stool, bed, couch, etc.). In some aspects,
the sensor node 104 can be embodied in objects found in a medical
setting, such as a doctor's office, a hospital, and the like. Such
specific examples include an examination chair, a hospital bed, and
the like. Further, although the user of FIG. 1 is illustrated as a
human, the user can be any biological entity with skin that permits
the transmission of electrical power and/or data.
[0032] With the skin-based transmission of electrical power and/or
data, the master hub 102 can estimate the locations of the sensor
nodes 104 on the body 106 via the time required for communication
signals to be transmitted and received from each sensor node 104,
also referred to as time-of-flight. The time-of-flight can be used
to approximate the distance between the master hub 102 and each
sensor node 104. Time-of-flight can be measured using various
methods. According to one method, the master hub 102 (or a sensor
node 104) can emit a known signal, such as a brief pulse. In some
aspects, the signal or brief pulse can include known content, such
as known broadband frequency content. As the signal or brief pulse
propagates across the body 106, the rate of change of phase with
frequency increases. By measuring the change in the signal, and
comparing the change to the original signal, the master hub 102 (or
sensor node 104) can determine the travel time. Because the
propagation speed of electrical signals through tissue is known,
the travel time can be related to the travel distance, such as the
travel distance between the master hub 102 and a sensor node 104,
or between two sensor nodes 104. Thus, based on the travel time,
the master hub 102 (or sensor node 104) can determine the distance
between it and another sensor node 104. The determination of
location can be based on a round trip (i.e., from the master hub
102, to the sensor node 104, and back to the master hub 102), or
based on a one-way trip (i.e., from the master hub 102 and to the
sensor node 104). In the case of a one-way trip, the sensor node
104 can be pre-programmed with information (e.g., known signal,
frequency, etc.) of the on the brief pulse sent by the master hub
102 to determine the travel time.
[0033] If the master hub 102 knows its location on the body 106,
based on the approximate distances between the master hub 102 and
the sensor nodes 104, the master hub 102 can determine where the
sensor nodes 104 are located on the body 106. With the known
locations, the master hub 102 can vary one or both of the
electrical power and data transmitted to the sensor nodes 104 based
on a correspondence between the location of the sensor nodes 104
and, for example, the functionality and/or sensor modality
associated with the location. In some aspects, the determination of
the sensor node locations based on the approximate distance is
sufficient for determining when and/or how to alter the electrical
power and/or data sent to the sensor node 104. However,
time-of-flight determination of the sensor node locations can be
combined with additional location determination methodologies, such
as location detection algorithms executed by the sensor nodes 104,
to provide a more accurate estimation of the locations of the
sensor nodes 104.
[0034] In some aspects, the sensor nodes 104 can be configured to
determine the locations of the other sensor nodes 104. The master
hub 102 can transmit electrical power and data to the sensor nodes
104 that cause the sensor nodes 104 to transmit location-related
data. The other sensor nodes 104 can then receive the
location-related data and respond back to the sensor nodes 104.
This communication arrangement allows the sensor nodes 104 to
determine the locations of the other sensor nodes 104 through
travel times of the data.
[0035] Referring to FIG. 2, FIG. 2 shows a schematic view of the
master hub 102 and the sensor nodes 104 of FIG. 1, in accord with
aspects of the present disclosure. Referring first to the master
hub 102, the master hub 102 includes, for example, a power source
200, memory 202, a power transmitter and data transceiver 204 for
communicating with the sensor nodes 104, a communications interface
206 for communicating with the computer device 108, and a processor
208.
[0036] The power source 200 provides the electrical power within
the master hub 102 and to the sensor nodes 104 within the system
100. To any extent the master hub 102 may be constrained by the
inclusion of an on-board power source 200, the location of the
master hub 102 on the body 106 can be independent of a specific
location. For example, whereas a sensor node 104 should be located
in a location related to the sensor modality, the master hub 102
can be remote from the location without impacting the sensing.
Thus, the placement of the master hub 102 within the system 100 is
not negatively impacted by the inclusion of the power source 200.
Further, the power source 200 can include various conventional
power sources, such as a super-capacitor or one or more
rechargeable or non-rechargeable batteries or cells having various
battery chemistries, such as lithium ion (Li-ion), nickel-cadmium
(NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), zinc and
manganese(IV) oxide (Zn/MnO.sub.2) chemistries, to name a few
examples. In some aspects, the power source 200 can be an
electrical wall outlet that the master hub 102 directly connects
to, or connects to through, for example, a power adapter (e.g.,
alternating current adapter). In some aspects, the power source 200
can be a component that harvests non-electrical energy, such as
thermal energy, kinematic energy, and/or radio-frequency energy,
and converts the energy into electrical energy. However, the power
source 200 can be various other power sources not specifically
disclosed herein.
[0037] The memory 202 stores various instructions and algorithms
for both the functioning of the master hub 102 and the sensor nodes
104. The memory 202 can be any type of conventional memory, such as
read only memory (ROM), read-write memory (RWM), static and/or
dynamic RAM, flash memory, and the like. In some aspects, data
received from the computer device 108 can be written to the memory
202 for updating the instructions and algorithms stored on the
master hub 102, such as for updating instructions and algorithms
based on newly developed sensor nodes 104. And data from the memory
202 can be written to memory of the sensor node 104 to reconfigure
them and, for example, update the firmware or other operating
instructions of the sensor node 104.
[0038] The power transmitter and data transceiver 204 can be
configured to transmit electrical power and data to the sensor
nodes 104. The power transmitter and data transceiver 204 is
configured to modulate the electrical power with the data, or data
signals (e.g., analog signals), to transmit the data on the carrier
of the electrical power. Thus, electrical power and data can then
be received by the sensor nodes 104 and demodulated and/or
rectified to cause the sensor nodes 104 to operate. More
specifically, the power transmitter and data transceiver 204
generates a time-varying electromagnetic wave that propagates
through the body 106 and is eventually received and rectified by
sensor nodes 104. The power transmitter and data transceiver 204
can include a transceiver circuit comprised of an amplifier whose
output drives an electrode coupled to the skin 106a. The
transceiver circuit can include components such as, but not limited
to, crystals, LC-tank oscillators, microelectromechanical system
(MEMs) oscillators, processor general-purpose input/output (GPIO)
ports, frequency synthesizers, and ring-oscillators to generate the
output. The power output can be controlled by modifying the gain of
the amplifier in real time. An adjustable impedance matching
network may be included so that the maximum power is transmitted
through the surface medium (e.g., skin 106a) to ensure the
electromagnetic wave optimally propagates. The adjustable impedance
matching network may include various capacitors, inductors, and
resistors using various techniques such as, but not limited to,
pi-matching, t-matching, and distributed matching networks.
[0039] The communications interface 206 can be any traditional
communications interface for communicating with the computer device
108, such as one based on the wireless communication protocols of
Wi-Fi, medical telemetry, Bluetooth, Bluetooth Low Energy, Zigbee,
and the like, for example, based on open 2.4 gigahertz (GHz) and/or
5 GHz on radiofrequencies, and the like. However, as described
above, the communications interface 206 can also support wired
communications with the computer device 108.
[0040] The processor 208 controls the operation of the master hub
102. The processor 208 can be various types of processors,
including microprocessors, microcontrollers (MCUs), etc., that are
capable of executing programs and algorithms, and performing data
processing. Specifically, the processor 208 executes one or more
instructions and/or algorithms stored in the memory 202 or
transmitted from the computer device 108, which cause the master
hub 102 to transmit electrical power and data to the sensor nodes
104, receive response data from the sensor nodes 104, and
aggregate, process, analyze, and/or store the response data. In
some aspects, the processor 208 analyzes and/or processes the
response data from the sensor nodes 104, such as the sensor
information, prior to transmitting the response data to the
computer device 108. In addition or in the alternative, the
processor 208 can simply cause the master hub 102 to transmit the
response data to the computer device 108, such as when the computer
device 108 is actively communicating with the master hub 102.
[0041] Referring to the sensor nodes 104 of FIG. 2, the sensor
nodes 104 can be location specific sensory platforms that are
placed at specific locations on the body 106 for location-specific
sensing. The sensor nodes 104 receive the transmitted electrical
power and data from the master hub 102 to execute sensing,
algorithms, and communicate back to the master hub 102. Further,
because the sensor nodes 104 receive the electrical power from the
master hub 102 required for operation, the sensor nodes 104 do not
include discrete power sources for the overall operation of the
sensor nodes 104 except that the sensor node can include power
storage components, such as capacitors and even small batteries to
provide power in the event of a temporary power disruption).
[0042] In some aspects, the sensor node 104 can stream sensor
information back to the master hub 102. Such a sensor node 104 can
be considered a simple node. Alternatively, the sensor node 104 can
store the sensor information on the sensor node 104 prior to
transmitting the sensor information to the master hub 102. Still
further, the sensor node 104 can alternatively process the sensor
information prior to transmitting the sensor information to the
master hub 102. Processing of the sensor information can include,
for example, smoothing the data, analyzing the data, compressing
the data, filtering the data, and the like. Such a sensor node 104
can be considered a smart node. Thus, the functionality of the
sensor node 104 can vary.
[0043] The configuration of the sensor nodes 104 can vary depending
on the specific modality and/or functionality of the sensor(s).
However, in general, the sensor nodes 104 include a processor 210,
one or more sensors 212, and an electrical power receiver and data
transceiver 214.
[0044] The processor 210 performs the digital signal processing and
data analysis of the sensor information generated and/or collected
by the one or more sensors 212. In some aspects, the data analyses
of the sensor information includes, for example, executing one or
more processes for smoothing the data, analyzing the data,
compressing the data, filtering the data, and the like. In some
aspects, the processing includes executing one or more stored or
transmitted (e.g., from the master hub 102) pattern recognition
algorithms to detect one or more pre-defined patterns in the data.
However, in some instances, the data or sensor information (e.g.,
raw data) can be streamed back to the master hub 102 without being
processed. Instead, for example, the processing and/or analyzing of
the data or sensor information can instead be solely performed at
the master hub 102 or the computer device 108. The processor 210
can be various types of processors, including microprocessors,
MCUs, etc., that are capable of executing algorithms and data
processing, particularly based on the lower electrical power levels
transmitted from the master hub 102. In some aspects, the processor
210 can include memory for storing one or more algorithms performed
by the sensor nodes 104, and for storing information transmitted
from the master hub 102. Alternatively or in addition, the sensor
nodes 104 may include memory that is independent from the processor
210. In some embodiments, the sensor nodes 104 are slave nodes or
dumb nodes and function based only on the data communication from
the master hub 102 and do not include instructions, algorithms, or
other data required for functioning. Alternatively, the sensor
nodes 104 can be smart nodes that receive electrical power and
triggering signals and/or instructions (e.g., data) from the master
hub 102, but include the necessary instructions, algorithms, or
data internally for generating and/or collecting sensor data and
transmitting sensor data and other information back to the master
hub 102. By way of example, and without limitation, the processor
210 can be a Cortex-M Series MCU by ARM.RTM. Ltd., an MSP430 MCU by
Texas Instruments Inc., and the like.
[0045] The one or more sensors 212 perform the sensing
functionality on the sensor nodes 104. The sensors 212 can be
various types of sensors having various types of sensing
modalities. According to some embodiments, the sensors 212 include
heat flux sensors, accelerometers or gyroscopes (e.g., motions
sensors), electrocardiogram (ECG or EKG) sensors, pressure sensors,
heart rate monitors, galvanic skin response sensors, sweat sensors,
non-invasive blood pressure and blood oxygen saturation monitors,
pedometers, optical sensors, acoustic sensors, blood glucose
sensors, and the like. However, the sensor nodes 104 can include
additional sensors not explicitly disclosed herein without
departing from the spirit and scope of the present disclosure. By
way of some specific examples, the one or more sensors 212 can
include an ADS1191 biopotential sensor by Texas Instruments, Inc.,
an ADXL362 accelerometer by Analog Devices, and the like.
[0046] In some aspects, one or more components of the sensor nodes
104 independent of the sensors 212 can be considered a sensor. For
example, components of the sensor nodes 104 configured to receive
electrical power and transmit and receive data can also be
configured for sensing. Specifically, electrical contacts used for
receiving the electrical power can be configured to function as
galvanic skin sensors, ECG or EKG sensors, and the like.
Accordingly, in some aspects, a sensor node 104 may not include a
sensor 212, per se, where the components of the sensor node 104
themselves are capable of sensing characteristics and/or properties
of the skin 106a and/or the body 106.
[0047] The electrical power receiver and data transceiver 214
allows the sensor nodes 104 to receive electrical power from the
master hub 102, and to receive data from and transmit data to the
master hub 102, as well as from and to the other sensor nodes 104
within the system 100. The transceiver 214 extracts the data and
the electrical power from the received signals to both power the
sensor node 104 and provide the data for executing algorithms and
processing data generated by the sensors 212. The data can include
instructions and/or commands to the sensor nodes as well as
firmware updates and other programs or algorithms to be executed by
the sensor node. The transceiver 214 functions based on the
properties of the skin 106a of the body 106 as described above with
respect to the power transmitter and data transceiver 204.
[0048] FIG. 3 shows a detailed schematic of the transceiver 214, in
combination with the processor 210, in accord with aspects of the
present disclosure. Although described with respect to the
transceiver 214, as mentioned above, the power transmitter and data
transceiver 204 of the master hub 102 can include similar
components as the transceiver 214 for transmitting and receiving
electrical power and data transmission. In some aspects, the
transceiver 214 includes one or more electrical contacts 300, a
biasing circuit 302, an amplifier 304, a demodulator 306, an
analog-to-digital converter 308, an alternating current drive
circuitry 310, and a power circuitry 312.
[0049] The electrical contacts 300 are formed of conductive
material (e.g., copper, silver, gold, aluminum, etc.) and provide
the interface between the sensor node 104 and the skin 106a, or the
sensor node 104 and the air gap between the sensor node 104 and the
skin 106a, for receiving electrical power and transmitting and
receiving data communication. The sensor node 104 may include one
or more electrical contacts 300. In some aspects, the sensor node
104 includes four contacts, with two contacts for receiving and two
contacts for transmitting. In some aspects, the contacts 300 can be
four contacts 300 configured as 4-wire measurement electrodes.
[0050] For alternating electrical power transmitted into the skin,
at around 300 kHz or higher, the alternating electrical power can
be detected non-contact to the signal for as far as a few
millimeters from the skin. Hence, the electrical contacts can be
operated without being in contact with the skin. Thus, in terms of
the master hub 102 discussed above, as well as the sensor nodes
104, the electrical contacts 300 do not need intimate coupling to
the skin. However, in some aspects, a master hub 102 configured
with electrical contacts that do not contact the skin is equipped
with a higher power transmitter. Without the requirement for direct
skin contact, the master hub 102 can be embodied in, for example, a
smart watch, a fitness tracker, or other device powered by a power
source that is loosely secured to the body 106, without always
being in direct contact with the skin 106a. Accordingly, both the
master hub 102 and the sensor nodes 104 can be skin mounted or
non-contact mounted. For skin-mounted nodes, the electrical
contacts are resistively coupled to the skin. For non-contact
mounted nodes, the electrical contacts are capacitively coupled to
the skin with a skin to electrode distance of less than a few
millimeters, such as less than or equal to about 3 mm.
[0051] As represented by the adjoining arrow, the contacts 300 can
be electrically connected to and in communication with a biasing
circuit 302, such as an analog front-end biasing circuit. The
biasing circuit 302 biases the data communication signal from the
master hub 102, or other sensor nodes 104, for further processing
by the components of the sensor node 104. The other components that
perform the processing include, for example, the amplifier 304,
which amplifies the data signal received from the master hub 102,
or other sensor nodes 104. As represented by the adjoining arrow,
the amplifier 304 can be electrically connected to and in
communication with the biasing circuit 302. The other components
also include the demodulator 306, which demodulates the electrical
power and data signal from the master hub 102 to separate the data
from the electrical power. As represented by the adjoining arrow,
the demodulator 306 can be electrically connected to and in
communication with the amplifier 304 for demodulating the amplified
data. In combination with the analog-to-digital converter 308, the
demodulator 306 digitizes the extracted data and forwards the
digitized data to the processor 210. As represented by the
adjoining arrows, the demodulator 306 can be directly electrically
connected to and in communication with both the analog-to-digital
converter 308 and to the processor 210. As represented by the 2-way
arrow, the processor 210 transmits information back to the
demodulator 306 for transmission to the master hub 102. By way of
example, and without limitation, the demodulator 306 can be a
synchronous demodulator and configurable analog filter, such as the
ADA2200 made by Analog Devices, Inc. Further, although described
herein as a demodulator, in some aspects, the demodulator 306 can
instead be a modem.
[0052] As represented by the adjoining arrow, the demodulator 306
can be electrically connected to and in communication with
alternating current drive circuitry 310. The alternating current
drive circuitry 310 generates alternating current pulses, or
response data, for communicating with the master hub 102 and,
potentially, with the other sensor nodes 104 within the system 100.
The alternating current drive circuitry 310 is controlled by the
processor 210 to generate the alternating current pulses for
responding to the master hub 102, and potentially the other sensor
nodes 104 within the system 100.
[0053] The power circuitry 312 controls the electrical power at the
sensor node 104 for executing algorithms and data processing based
on the electrical power from the master hub 102. In some
embodiments, the power circuitry 312 includes a capacitor or
similar type of temporary power storage component that stores power
received from the master hub 102 during execution of the algorithms
and processing of the data or sensor information. However, the
power stored in the capacitor or similar type of temporary power
storage component is received from the master hub 102, rather than
being originally in the power source itself, such as in a chemical
energy power source (e.g., battery).
[0054] Although electrical power and data transmission signals can
be transmitted through the skin 106a, noise may be introduced into
signals. In part because of the noise, time stamping of the signals
presents some issues. Accordingly, the above described circuitry of
the master hub 102 and the sensor nodes 104 include circuitry to
remove the noise and recover the underling signals. In some
aspects, the circuitry is a phase lock loop (PLL). Moreover, most
physiological sensors generate data less than a few hundred bytes a
second. Data communication at about 300 to about 1200 baud is
enough for transmitting real time data for the sensors and the
corresponding sensor nodes 104. A noise rejecting circuit based on
a PLL with a carrier frequency between about 100 kHz and about 300
kHz, and a bandwidth of about 30 kHz, can transmit data
communication at 1200 baud with simple communication scheme.
Moreover, such a noise rejecting circuit can also detect the
electrical current pulses described above, as well as measure
bioimpedance. Based on this arrangement, as many as about 66
channels, one for each sensor node 104, can be allocated.
[0055] Although not shown, in some aspects, the sensor nodes 104
can include wired interfaces for connecting to one or more external
sensors or other nodes within the system 100. The wired interfaces
can be various types of interfaces, particularly for connecting to
components that use low power, such as an I.sup.2C interface and
the like. Further, in some aspects, the sensor nodes 104 include
components that provide for near-field communication (NFC)
capability, or other similar low-power, wireless communication
protocols, for episodic sampling upon interrogation by a reader.
For example, in addition to one or more electrical contacts for
receiving the electrical power and data from the master hub 102,
the sensor nodes 104 can include a wire coil for interrogation by a
NFC-capable smart device (e.g., smartphone, tablet, and the
like).
[0056] Referring to FIG. 4, FIG. 4 is a timing diagram of
electrical power and data transmission within the on-body,
multi-sensor system 100 of FIG. 1, including data synchronization,
in accord with aspects of the present disclosure. The transmission
of the electrical power and data relies on an electrical current
being able to travel across the skin 106a of the body 106, similar
to an electrical current traveling through water. Indeed, the
propagation velocity of the electrical current across the skin 106a
is approximately one-tenth of the speed of light. Further, the
longest conductive path between any two points on the body 106 is
about 2 meters. Therefore, the signal propagation delay of an
electrical signal from one point to another point across the body
106 is about 70 nanoseconds (ns). This delay is below the
synchronization requirement of a majority of the physiological
sensors for proper interpretation of the signals.
[0057] For synchronization, the master hub 102 first transmits an
electrical current pulse 400a into the skin 106a of the body 106.
The electrical current pulse 400a is of a fixed duration and
amplitude, or amplitude pattern, and at a dedicated frequency
channel for initial synchronization. According to some aspects, the
master hub 102 continuously, periodically, semi-periodically, or
on-demand transmits the electrical current pulse 400a so that
sensor nodes 104 newly placed on the body 106 can be synchronized
within the system 100.
[0058] The sensor nodes 104 on the body 106 then detect the
electrical current pulse 400a, as shown by the received electrical
current pulses 402a-402n (collectively received current pulses
402). The sensor nodes 104 detect the electrical current pulse 400a
with less than about 1 microsecond (.mu.s) of a delay. The sensor
nodes 104 then transmit acknowledge pulses 404a-404n (collectively
acknowledge pulses 404) after a pre-determined delay and for the
master hub 102 to detect, as indicated by the received current
pulse 400b. A synchronized signal acquisition can then be
undertaken by the sensor nodes 104. Specifically, the master hub
102 transmits an electrical power and data pulse 400c, which
triggers the synchronized signal portions 406a-406n (collectively
synchronized signal portions 406). The electrical current pulse
400c is of a fixed duration and amplitude, or amplitude pattern,
and at a dedicated frequency channel for triggering, which is
different than the initial frequency initialization channel. The
timing and synchronization scheme and system architecture to
perform sensor synchronization and measurement triggering disclosed
above enables sensor nodes 104 to synchronize at time delays less
than 1 .mu.s and power levels of about 1.5 milliwatts (mW), which
is lower than radio frequency wireless communication.
[0059] Referring to FIGS. 5A and 5B, an exemplary sensor node 500
is shown, in accord with aspects of the present disclosure. By way
of example, and without limitation, the sensor node 500 may be a
conformal sensor node formed of a flexible substrate and circuit
for conformal attachment to the surface (e.g., skin 106a) of a
user. The sensor node 500 is configured to generate sensor
information associated with the user upon which the sensor node 500
is attached.
[0060] FIG. 5A shows the bottom of the sensor node 500, and FIG. 5B
shows the top of the sensor node 500. As shown in FIG. 5A, the
sensor node 500 includes four contacts 502 (e.g., contacts 300).
The contacts 502 contact the skin 106a of a user to receive and
transmit signals, such as the electrical power and/or data, from
and into the skin. However, in some embodiments, a small air gap
can be between the contacts 502 and the skin 106a, and the signals
can be transmitted across the air gap, as described above.
[0061] In some aspects, two of the contacts 502 are electrically
configured and/or wired within the circuit of the sensor node 500
to receive the electrical power and/or data, and the other two of
the contacts 502 are electrically configured and/or wired within
the circuit of the sensor node 500 to transmit electrical power
and/or data. However, in some aspects, all of the contacts 502 can
be electrically configured and/or wired to both transmit and
receive the electrical power and/or data. Further, although only
four contacts 502 are shown, the number of contacts may vary. For
example, the sensor node 500 may have one or more contacts 502.
[0062] As described above, the contacts 502 may also be used by the
sensor node 500 to generate sensor information. For example, the
sensor node 500 may be a galvanic skin sensor. One or more of the
contacts 502 may be electrically configured and/or wired to
generate sensor information with respect to, for example,
bioimpedance, in addition to receiving and transmitting electrical
power and/or data. Thus, in the case of sensor node 500, the
sensors (e.g., sensors 212) are, in part, the contacts 502.
[0063] The sensor node 500 further includes sets of vertical
interconnects accesses (VIAs). Specifically shown in FIG. 5A are
the bottoms 504 of the sets of VIAs. The VIAs transfer the
electrical power and/or data between layers of the circuits of the
sensor node 500. For example, the bottoms 504 of the sets of VIAs
are electrically connected to the contacts 502 to transfer the
electrical power and/or data from a bottom circuit layer of the
sensor node 500 to a top circuit layer of the sensor node 500.
[0064] Referring to FIG. 5B, FIG. 5B shows the tops 506 of the sets
of VIAs. The tops 506 of the sets of VIAs are electrically
connected to a top circuit layer of the sensor node 500 for
providing the electrical power and/or data to the top circuit
layer. With respect to the sensor node 500, the sensor node 500
includes one or more components within the top circuit layer for
analyzing and/or processing the electrical power and/or data signal
received by the contacts 502. For example, although not shown, the
sensor node 500 can include the processor 210 and the transceiver
214 above the tops 506s of the VIAs. The processor 210 and the
transceiver are electrically connected to the tops 506 of the VIAs
so as to be electrically connected to the contacts 502. Based on
the processor 210 and the transceiver 214 being electrically
connected to the contacts 502, the processor 210 rectifies the
electrical power and the transceiver demodulates the data received
at the contacts 502. The processor 210 can then process the sensor
information to be transmitted back to a master hub (e.g., master
hub 102) through the contacts 502 and the skin 106a of the body
106. In some aspects, the sensor node 500 further includes a
grounding line 508.
[0065] According to the configuration of the sensor node 500, the
sensor node 500 can be placed on various locations of the body 106.
Further, because the sensor node 500 does not have an on-board
power source, the sensor node 500 receives the electrical power for
operation by receiving electrical power transmitted from a master
hub (e.g., master hub 102) located on the body 106 but remote
(e.g., not directly connected) from the sensor node 500. The
electrical power, along with the data from the master hub 102, is
received by one or more of the contacts 502 and electrically powers
the sensor node 500.
[0066] Referring to FIGS. 6A-6C, a master hub 600 is shown coupled
to the body 106 of a user, in accord with aspects of the present
disclosure. Referring to FIG. 6A, the master hub 600 may be, for
example, integrated into a smart watch. Specifically, the master
hub 600 may be integrated into the wristband of the smart watch.
However, the master hub 600 can be integrated into any one of the
devices discussed above. Based on the master hub 600 being
integrated into a smart watch, or the wrist band of the smart
watch, the master hub 600 is attached to, for example, the skin
106a around the wrist of the user's body 106.
[0067] Although not shown (for illustrative convenience), the
master hub 600 includes a power source (e.g., power source 200).
The power source powers both the master hub 600 and the smart
watch, such as the time keeping functionality and the
communications functionality of the smart watch with an off-body
device (e.g., computer device 108), such as a smartphone that is
communication with the smart watch, etc.
[0068] Referring to FIG. 6B, the master hub 600 includes contacts
602. Although four contacts 602 are shown, the master hub 600 can
have one or more contacts. Similar to the contacts 502, the
contacts are made of a conductive material (e.g., copper, silver,
gold, aluminum, etc.). Through the contacts 602, the master hub 600
transmits and receives electrical power and/or data to and from the
skin 106a. The contacts 602 may be in contact with the skin 106a.
Alternatively, the contacts 602 may not be in contact with the skin
106a. For example, depending on how loose the wristband is, the
contacts 602 may not always be in contact with the skin 106a.
[0069] Referring to FIG. 6C, FIG. 6C shows a gap 604 that may be
between the contacts 602 (FIG. 6B) and the skin 106a. Despite the
gap 604, the higher energy reserve of the smart watch allows the
master hub 600 to transmit electrical power and/or data across the
air gap 604, as discussed above. For example, as discussed above,
at around 300 kHz or higher, alternating current signals can be
detected non-contact to the skin 106a for as far as a few
millimeters from the skin 106a. Therefore, the master hub 600 can
be operated non-contact while still enabling electrical power
and/or data transfer into the skin.
[0070] Although the foregoing disclosure is generally related to
transmitting electrical power and data transmission between the
master hub 102 and the sensor nodes 104, according to some aspects,
only electrical power or only data can be transmitted between the
master hub 102 and the sensor nodes 104. For example, only
electrical power can be transmitted by the master hub 102 to the
sensor nodes 104 for smart sensor nodes 104 that do not require
transmitted data.
[0071] According to the above disclosure, the system 100 enjoys
benefits over other multi-sensor systems on a user's body. For
example, the system 100 can be used in applications where
multi-modal sensing is required, and where the specific modality of
the sensing may vary across users or may vary over time for the
same user. For example, a user who wishes to go for a run can use
the system 100 to log heart rate, gait, posture, and sweat rate by
using sensor nodes 104 optimized for each of these sensing
modalities. The master hub 102 can aggregate the data from each
sensor node 104, fusing the data into insightful characteristics
about the activity the user is performing. Moreover, a user can
quickly and easily change the modalities of the system by changing
the sensor nodes 104 on the user's body. Further, the form factor
of the sensor nodes 104 can be smaller, less obtrusive, and more
conformal, while still enjoying the benefits of, for example,
continuous data generation by an on-body node (e.g., master hub
102) rather than, for example, periodic data generation based on
interrogation of the sensor nodes 104 by an off-body computer
device.
[0072] Other embodiments are within the scope and spirit of the
invention. For example, due to the nature of software, functions
described above can be implemented using software, hardware,
firmware, hardwiring, or combinations of any of these. Features
implementing functions may also be physically located at various
positions, including being distributed such that portions of
functions are implemented at different physical locations.
[0073] Further, while the description above refers to the
invention, the description may include more than one invention.
* * * * *